Fix formatting in colab_tpu.rst

Author: jonbrenas

docs/source/colab_tpu.rst

@@ -107,4 +107,4 @@ Check which version of ``blinker`` is installed:
     pip show blinker
     python -c "import blinker; print(blinker.__version__)"
 
-If version ``1.4`` is installed under ``/usr/lib/python3/dist-packages``, this indicates the TPU system package.
+If version ``1.4`` is installed under ``/usr/lib/python3/dist-packages``, this indicates the TPU system package.